Key telephone set



FIG. 1 is a front elevational view of a key telephone set showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof;

FIG. 7 is a perspective view thereof with the handset removed. 

The ornamental design for key telephone set, as shown and described. 